Double slash in css file path

There is a bug in the code- this appears on your demo site as well as my live site.

Double slash appears for the following css file: <link href="/media/jub/assets//css/bootstrap-core.min.css" rel="stylesheet" type="text/css" />

Please provide file path/instructions to fix

We're having issue with the server of JA Builder, once it's back, we will check this issue. Kindly wait.